Autonomic tests measure how the systems in the body that are controlled by the autonomic nerves respond to stimulation. The data collected during testing will indicate if the autonomic nervous system is functioning as it should, or if nerve damage has occurred.
What is Autonomic Testing?
The nervous system has three parts: motor , sensory and autonomic. The autonomic system manages all internal functions such as blood pressure, blood flow, and sweating. Autonomic tests are conducted to see if the autonomic nervous system is functioning normally.
Purpose of Autonomic Testing
Autonomic testing can help determine if a patient is suffering from certain diseases that attack the autonomic nervous system, or as a way to diagnose an illness, or source of pain.
How is Autonomic Testing Done?
To see if a disease is affecting the autonomic nervous system, several tests  are done to monitor blood pressure, blood flow, heart rate, skin temperature, and sweating. By measuring these functions, it is possible to discover whether or not the autonomic nervous system is functioning normally.
Tests to measure blood pressure and heart rate include the tilt table test, a deep breathing test and the Valsalva maneuver. The tilt table test requires that the patient lie on a table that is then raised. The deep breathing test requires the patient to take deep breaths for a minute. The Valsalva maneuver requires that the patient blow into a tube to increase pressure in the chest. While these simple tests are performed, blood pressure and heart rate are monitored.
The Quantitative Sudomotor Axon Reflex Test (QSART)  described separately, is another autonomic test performed to measure sweating and skin temperature.
Does Autonomic Testing Hurt?
All testing is non-invasive and painless.